Merge r579664 from trunk:

Reinstate location walk for subrequests
PR 41960 (Jose Kahan)

Submitted by: niq
Reviewed by: jim


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.2.x@655540 13f79535-47bb-0310-9956-ffa450edef68